Disposable polymer-structured filter

ABSTRACT

The disposable polymer-structured filtering kit includes a disposable, polymer-structured filtering funnel with a stem having a distal tip. A flow discharge end is formed at the distal tip. Preferably, a polymer fritted filter disc is positioned in the funnel, providing filtering for liquids passing therethrough. The kit preferably also includes a glass vacuum take-off adapter having a port for connecting to a vacuum source for providing negative pressure. The adapter securely and snuggly receives the funnel and maintains position of the distal tip thereof with the flow discharge end below the port, thus preventing contaminants from entering the adapter. A reusable, glass round bottle flask or a disposable vial receives the adapter and the stem of the funnel. The funnel and fritted disc are formed from disposable materials, thus removing the necessity of cleaning them following use. The adapter is reusable, since no contaminants come in contact therewith during filtering.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/136,141, filed Aug. 14, 2008.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to laboratory glassware, and particularlyto a disposable polymer-structured filtering kit for use in small-scalevacuum filtration of solid-liquid samples.

2. Description of the Related Art

Vacuum filtration, a common technique used in chemistry laboratories,involves passing a liquid containing a solid through a porous interfaceso that the solid can be trapped as the liquid flows therethrough.Typically, a vacuum filtration kit for small-scale filtration includes afilter funnel, an adapter and a receiving receptacle.

A typical vacuum filtration kit using the above three components has avacuum port formed through the filter funnel. Such a kit typicallyincludes a glass filter funnel with a vacuum take-off port connected toa vacuum source and a glass filtrate receptacle for receiving thesolution. The funnel typically has a ground joint for coupling with afiltrate receptacle, and has a fritted glass filter disc for filteringany insoluble materials.

Another typical vacuum filtration kit may have a vacuum take-off portintegrated into the adapter. The kit includes a glass filtering funnelwithout a ground joint, the glass adapter with the vacuum take-off port,a rubber adapter for coupling with the funnel, and a receptacle forreceiving filtrate.

In yet another typical vacuum filtration kit, a vacuum take-off port isintegrated into a filtrate receptacle. The kit includes a filteringfunnel, the filtrate receptacle with the vacuum take-off port, and arubber adapter for coupling the funnel with the filtrate receptacle.

With each of these vacuum filtration kits, during the filtrationprocess, the fluid to be filtered is placed into the funnel and thefiltrate receptacle is attached. Negative pressure from the vacuum isapplied to the vacuum take-off port. The pressure differential caused bythe vacuum causes the fluid to pass through the filter and into thereceptacle. Thus, the insoluble material is collected on the fritteddisc.

Following usage, all of the components of the vacuum filtration kit mustbe cleaned in order to eliminate contamination. However, the glasswareis susceptible to accidental breakage and shattering during the cleaningprocess, particularly since some of the components are difficult toclean by hand. Some of the above components are relatively expensive toreplace, particularly the glass filter funnel with the glass fritteddisc filter, because these are typically made by hand. Additionally, thecleaning process is quite time consuming, particularly when viewed inthe laboratory setting, where time is an important factor in manyexperiments. Thus, a disposable polymer-structured filtering kit solvingthe aforementioned problems is desired.

SUMMARY OF THE INVENTION

In a first embodiment, the disposable polymer-structured filtering kitincludes a disposable, polymer-structured filtering funnel with a stemhaving a distal tip. A flow discharge end is formed at the distal tip.Preferably, a polymer fritted filter disc is positioned in the funnel,providing filtering for liquids passing therethrough. The kit preferablyalso includes a glass vacuum take-off adapter having a port forconnecting to a vacuum source for providing negative pressure. Theadapter securely and snuggly receives the funnel and maintains positionof the distal tip thereof with the flow discharge end below the port,thus preventing contaminants from entering the adapter. A reusable,glass round bottle flask receives the adapter and the stem of thefunnel. The funnel and fritted disc are formed from disposablematerials, thus removing the necessity of cleaning them following use.The adapter does not need to be cleaned and can be reused, since nocontaminants come in contact therewith during filtering. The kit is welladapted for collecting either filtrate or insoluble material.

In an alternative embodiment, the disposable, polymer-structuredfiltering kit includes a disposable, polymer-structured filtering funnelwith a stem having a distal tip. A flow discharge end is formed at thedistal tip. The funnel also preferably has a relatively wide top openingfor easily receiving a liquid sample. A polymer fritted filter disc isalso positioned in the funnel to provide filtering. The kit furtherincludes a screw-threaded joint adapter having a port for connection toa vacuum source to provide negative pressure. The adapter securely andsnuggly receives the funnel and maintains position of the distal tipthereof with the flow discharge end below the port, thus preventingcontaminants from entering the adapter.

A disposable glass screw-threaded receiving vial is coupled to theadapter by the screw-threaded joint. The vial further receives the stemof the funnel, with the flow discharge end thereof being positioned inthe vial. The funnel and fritted disc are formed from disposablematerials, thus removing the necessity of cleaning them following use.The vial may also be unscrewed from the adapter for disposal. Theadapter does not need to be cleaned and can be reused, since nocontaminants come in contact therewith during filtering.

In a further alternative embodiment, the disposable polymer-structuredfiltering kit includes a disposable polymer-structured filtering funnel.The funnel has a detachable stem with a distal tip, a relatively widetop opening for easily receiving a liquid sample, and a flow dischargeend positioned at the distal tip. The kit further includes a polymeradapter for securely and snuggly receiving the funnel and positioningthe distal end thereof (with the flow discharge end) below the adapter.A polymer fritted filter disc is positioned between the funnel barreland funnel base to provide filtering. An Erlenmeyer filtering flaskhaving a vacuum port receives the adapter and the stem of the funnel,with the flow discharge end being positioned in the flask beyond theport. As above, the funnel and fritted disc are formed from disposablematerials, thus removing the necessity of cleaning them following use.Further, the adapter does not need to be cleaned and can be reused,since no contaminants come in contact therewith during filtering. As afurther alternative, a kit may be provided including a disposablepolymer-structured filtering funnel, a glass vacuum take-off adapter,and reusable glass flask or disposable vial, as described above. Thefunnel, adapter and flask or vial may have any of the above-describedconfigurations, but with the flask or vial being positioned within theadapter, rather than beneath it, as in the previous embodiments.

These and other features of the present invention will become readilyapparent upon further review of the following specification anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a disposable polymer-structuredfiltering kit according to the present invention.

FIG. 2 is a perspective view of an alternative embodiment of thedisposable polymer-structured filtering kit according to the presentinvention.

FIG. 3 is a perspective view of another alternative embodiment of thedisposable polymer-structured filtering kit according to the present.

FIG. 4 is a side view of a disposable polymer-structured filter funnelof the disposable polymer-structured filtering kit of FIG. 1.

FIG. 5 is a side view of a disposable polymer-structured filter funnelof the disposable polymer-structured filtering kit of FIG. 2.

FIG. 6 is a partially exploded, perspective view of a disposablepolymer-structured filter funnel of the disposable polymer-structuredfiltering kit of FIG. 3.

FIG. 7 is a side view of a vacuum take-off adapter of the disposablepolymer-structured filtering kit of FIG. 1.

FIG. 8 is a partially exploded view of a vacuum take-off adapter of thedisposable polymer-structured filtering kit of FIG. 2.

FIG. 9 is a partially exploded view of an alternative vacuum take-offadapter of the disposable polymer-structured filtering kit of FIG. 1.

FIG. 10 is a partially exploded view of an alternative vacuum take-offadapter of the disposable polymer-structured filtering kit of FIG. 2.

FIG. 11 is a side view of a polymer adapter of the disposablepolymer-structured filtering kit of FIG. 3.

FIG. 12 is a partially exploded side view of an alternative polymeradapter of the disposable polymer-structured filtering kit of FIG. 3.

FIG. 13 is a side view of a disposable glass-receiving receptacle of thedisposable polymer-structured filtering kit of FIG. 2.

FIG. 14 is a side view of an alternative embodiment of a vacuum take-offadapter of the disposable polymer-structured filtering kit of FIG. 1having a straight vacuum arm and a stopcock disposed in the arm.

FIG. 15 is a partially exploded view of another alternative embodimentof a vacuum take-off adapter of the disposable polymer-structuredfiltering kit of FIG. 2 having a straight vacuum arm and a stopcockdisposed in the arm.

FIG. 16 is a side view of an alternative embodiment of a disposablepolymer-structured filter funnel of the disposable polymer-structuredfiltering kit according to the present invention, the funnel beingconical and having a fritted filter disk or a polymer disk supported byan annular flange in the funnel bowl.

FIG. 17 is a side view of another alternative embodiment of a disposablepolymer-structured filter funnel of the disposable polymer-structuredfiltering kit according to the present invention, the funnel beingconical and having a polymer plate disposed in the funnel bowl.

FIG. 18 is a side view of another alternative embodiment of a disposablepolymer-structured filter funnel of the disposable polymer-structuredfiltering kit according to the present invention, the funnel beingcylindrical and having a fritted filter disk or polymer disk supportedby an annular flange in the funnel bowl.

FIG. 19 is a perspective view of another alternative embodiment of adisposable polymer-structured filter funnel of the disposablepolymer-structured filtering kit according to the present invention, thefunnel being cylindrical and having a polymer plate disposed in thefunnel bowl.

FIG. 20 is a plan view of an alternative embodiment of a filter disc ofthe disposable polymer-structured filtering kit according to the presentinvention, showing the hole pattern.

FIG. 21 is a plan view of another alternative embodiment of a filterdisc of the disposable polymer-structured filtering kit according to thepresent invention, showing a pattern of slits or slots.

FIG. 22 is a side view of another alternative embodiment of thedisposable polymer-structured filtering kit according to the presentinvention.

Similar reference characters denote corresponding features consistentlythroughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to disposable polymer-structured filteringkits. The kits, as will be described in detail below, each includedisposable polymer-structured filter funnels, non-disposable adapters,and glass receptacles.

With reference to FIG. 1, a first embodiment of the disposablepolymer-structured filtering kit, generally indicated by numeral 100, isshown. The kit 100 includes a disposable polymer-structured filteringfunnel 110, a glass vacuum take-off adapter 112, and reusable glassround bottle flask 114.

The funnel 110 has a stem 115 which, as shown, is relatively long andhas a flow discharge end 116 formed at the distal tip thereof. The stem115 is relatively long such that the flow discharge end 116 extends pastthe glass vacuum take-off adapter 112 and into the reusable glass roundbottle flask 114, as shown. The flow discharge end 116 extends into theflask 114 so as to prevent contamination of adapter 112 by filtrate whenunder negative pressure from an attached vacuum source (not shown). Thepolymer fritted filter 119 is placed on the bottom of the barrel 118 offunnel 110 for trapping insoluble materials. The funnel 110 furtherincludes an inner joint 117 positioned between the stem 115 and barrel118. The inner joint 117 provides a snug and secure fit between thefunnel 110 and the adapter 112.

The glass vacuum take-off adapter 112 has a vacuum take-off port 120 forconnection to the vacuum source, a funnel ground joint 122, and a bottomflask ground joint 124. The funnel ground joint 122 receives the stem115 of the funnel 110 and the inner joint 117 of the funnel 110 fits thefunnel ground joint 122. The stem 115 passes through the bottom flaskground joint 124 and is positioned such that the flow discharge end 116is received within the flask 114, as shown. The flask 114 is a commonlyused receptacle in chemistry laboratories, and it should be understoodthat the contouring and relative dimensions of flask 114 are shown forexemplary purposes only.

After filtration is complete, the funnel 110 is removed, safelydiscarded and disposed of, and replaced with another disposablepolymer-structured filtering funnel. The adapter 112 does not need to bereplaced, as the length of the stem 115 of the funnel 110 positions thedistal end of the flow discharge end 116 within the flask 114, past thevacuum take-off port 120, thus removing the risk of contamination duringfiltration. The flask 114 is cleaned and may be reused.

FIG. 2 illustrates an alternative embodiment of the disposablepolymer-structured filtering kit, generally indicated by numeral 200.The kit 200 includes a disposable polymer-structured filtering funnel210, a screw-threaded joint adapter 212, and a removable and disposableglass screw-threaded receiving vial 214.

Funnel 210 has a stem 215 that is relatively long, as shown, with a flowdischarge end 216 formed at the distal tip thereof. As in the previousembodiment, the stem 215 is long so that the flow discharge end 216extends past the screw-threaded joint adapter 212 and into thedisposable glass screw-threaded receiving vial 214. The flow dischargeend 216 extends into the vial 214 such that the adapter 212 is notcontaminated by filtrate when under negative pressure generated by thevacuum source. The polymer fritted filter disc 219 is placed on thebottom of the barrel 218 for trapping any insoluble materials. Thefunnel 210 further includes an inner joint 217 formed between the stem215 and barrel 218. The inner joint 217 provides a snug and secure fitbetween the funnel 210 and the adapter 212. The funnel 210 alsopreferably has a relatively wide top opening 225, allowing for easyinsertion therein of the liquid sample.

The screw-threaded joint adapter 212 includes a vacuum take-off port 220for connecting to the vacuum source for providing negative pressure,along with a funnel ground joint 222 and a bottom vial joint 224. Thebottom vial joint 224 is threaded to releasably screw on to the adapter212 and the vial 214.

The funnel ground joint 222 receives the stem 215 of the funnel 210, andthe inner joint 217 of the funnel 210 fits the funnel ground joint 222.The stem 215 passes through the bottom vial joint 224 such that the flowdischarge end 216 is positioned within the vial 214. The vial 214 ispreferably disposable.

Following filtration, the funnel 210 is removed, safely discarded anddisposed of, and replaced with another disposable polymer-structuredfiltering funnel. The adapter 212 does not need to be replaced, becausethe length of the stem 215 of the funnel 210 positions the flowdischarge end 216 thereof within vial 214, thus placing end 216 past thevacuum take-off port 220. The vial 214 may be easily removed, because itis removably screwed on to the adapter 212, and may be discarded. Thekit 200 is preferred for either taking filtrate or taking insolublematerials that are collected by the fritted disc 219.

With reference to FIG. 3, a further alternative embodiment of thedisposable polymer-structured filtering kit, generally indicated bynumeral 300, is shown. The kit 300 includes a disposablepolymer-structured filtering funnel 310, an adapter 312, and anErlenmeyer shaped filtering flask 314 with a vacuum port 320.

A funnel base 321 (best seen in FIG. 6) has a stem 315 that isrelatively long with a flow discharge end 316 formed at the distal tip.As in the previous embodiments, the stem 315 is long so that the flowdischarge end 316 extends past the adapter 312, into the Erlenmeyershaped filtering flask 314, and past the vacuum port 320 of the flask314. The flow discharge end 316 extends past the vacuum port 320 suchthat the filtrate does not contaminate the adapter 312 during vacuumfiltration. The funnel base 321 further includes an inner joint 317 atthe top of the stem 315. The inner joint 317 provides a snug fit withthe adapter 312. The funnel 310 also preferably has a relatively widetop opening 325, for easy reception of the liquid sample. Additionally,a clamp 327 is preferably provided for holding the funnel barrel 318 tothe funnel base 321, with the polymer fritted filter disc 319 beingpositioned therebetween.

The adapter 312 has a glass funnel ground joint 322 and a polymerstopper joint 324. The glass funnel ground joint 322 receives the stem315 of the funnel 310, and the inner joint 317 of the funnel 310 fitsthe funnel ground joint 322. The stem 315 then passes through thepolymer stopper joint 324 and is positioned such that the flow dischargeend 316 is located below the vacuum port 320 of the flask 314.

After filtration is complete, the funnel 310 is removed, safelydiscarded and disposed of, and replaced with another disposablepolymer-structured filtering funnel. The adapter 312 does not need to bereplaced, because the length of the stem 315 of the funnel 310 and thepositioning of the distal end of the flow discharge end 316 within flask314 is positioned beyond the vacuum take-off port 320 of the flask 314,thus preventing contamination of adapter 312. Fritted disc 319 cansimilarly be disposed of. The kit 300 is preferred for taking insolublematerials that are collected by the fritted disc 319, since the funnel310 can be disassembled so that the solid materials are easily removed.

FIG. 4 better illustrates the disposable polymer-structured filterfunnel 110 of FIG. 1. The disposable filter funnel 110 is preferablybarrel-shaped, having an open upper end 125 and a lower stem 115 havinga flow discharge end 116. Funnel 110, formed from a low cost polymermaterial, and fritted filter disc 119 are both disposable and may beeasily replaced.

The filtering funnel 110 and fritted filter disc 119 must resistcorrosion from various organic solvents. Accordingly, an inexpensivepolypropylene is preferably selected as the material of funnel 110.However, other polymer materials may also be utilized, such as acrylic,polycarbonate, styrene, polyfluoroethylene, polyvinylidene fluoride, orpolyethylene. The minimum length of the stem 115, to position the flowdischarge end 116 within flask 114, is preferably approximately twentymm. The preferred length for the stem 115 is approximately eighty mm.The top end of the stem 115 includes inner joint 117, which fits thefunnel ground joint 122 of the glass adapter 112 tightly to preventleaking. The size of inner joint 117 is preferably between approximatelyfive and sixteen mm in diameter, and between approximately five andtwenty mm in length. It should be understood that the funnel 110 may beused in combination with the filtering kits of FIGS. 2 and 3. Anexemplary internal volume for 110 is approximately 40 mL.

FIG. 5 illustrates the disposable polymer-structured filter funnel 210of FIG. 2. Funnel 210 preferably has a relatively wide top opening 225,as shown, and has contouring and dimensions similar to those describedabove with regard to funnel 110. However, barrel 218 has an open upperend 225. The top end of the stem 215 has an inner joint 217, which fitsthe funnel ground joint 222 of the glass adapter 212 tightly to preventleaking. The size of inner joint 217 is preferably between five andsixteen mm in diameter, and from between five and twenty mm in length.It should be understood that the funnel 210 may be used in combinationwith the filtering kits of FIGS. 1 and 3. As noted above, funnel 210 isdesigned for relatively small quantities of fluid. The exemplaryinternal volume for funnel 110 is given above as being approximately 40mL. A corresponding exemplary internal volume for funnel 210 is 18 mL.It should be understood that the funnels may have any desireddimensions, or be provided in sets of varying sizes, dependent upon theparticular needs of the user.

FIG. 6 illustrates the disposable polymer-structured filter funnel 310for trapping solid samples of FIG. 3. The barrel 318 has an open top end325 and an open bottom end 328. The barrel 318 uses a wider open end 325(similar to that described above with regard to upper end 225 of funnel210) for transferring relatively small volumes of fluid samples. Theopen bottom end 328 is provided for easily removing solid samples fromthe funnel 310.

A concavity 329 is formed at the top end of the funnel base 321, asshown. The filter disc 319 is placed in the concavity 329, enclosing thefilter disc 319 when the kit is assembled. The metal clamp 327 is usedto tightly clamp bottom end 328 of the barrel 318 and the top end of thebase 321. As shown, the barrel 318 forms an upper portion of the funnel,with the stem 317 forming a detachable lower portion. This arrangementis adapted for trapping solid samples and transferring relatively smallvolumes of liquid samples. It should be understood that the funnel 310may be used in combination with the filtering kits of FIGS. 1 and 2.Preferably, filter discs 119, 219 and 319 are formed from a polymermaterial, such as polyethylene, for example, having a relatively coarseor medium porosity. Alternatively, a conventional glass fritted filterdisc may also be utilized.

FIG. 7 illustrates the vacuum take-off adapter 112, with a bottom flaskground joint 124 and the funnel ground joint 122, of FIG. 1. The vacuumtake-off port 120 is formed on the side of adapter 112 for connection tothe vacuum source. The funnel ground joint 122 on the top end is coupledwith inner joint 117 of the funnel 110, and is preferably betweenapproximately five and sixteen mm in diameter, and between five andtwenty mm in length. The bottom flask ground joint 124 coupled with thereceiving receptacle or flask 114 preferably is manufactured in sizes of14/20, 19/22, 24/25, 24/40 or 29/42. As is conventionally known, a sizeof 14/20, for example, means, that the bottom flask ground joint 124 isfourteen mm in diameter, and twenty mm in length. The bottom groundjoint 124 fits reusable glass round bottle flasks, such as exemplaryflask 114 of FIG. 1. Adapter 112 is preferably formed from conventionalglass, though, alternatively, may be formed from a polymer material,metal or any other suitable material. FIG. 14 illustrates an alternativeembodiment of adapter 112 in which stopcock or valve 121 may beintegrated into the vacuum take-off port 120 in order to adjust thevacuum and prevent the filtrate from being sucked into the vacuum line.

FIG. 8 illustrates the vacuum take-off adapter 212, with a bottom vialjoint 224 and the funnel ground joint 222, of FIG. 2. The vacuumtake-off glass adapter 212, which is designed for coupling withdisposable glass vial 214, is shown joined to vial 214 in FIG. 2. Theadapter 212 includes funnel ground joint 222 on its top end, a bottomvial joint 224 on its bottom end, and a vacuum take-off port 220projecting from its side. The funnel ground joint 222 fits the innerjoint 217 of the funnel 210, and is preferably between five and sixteenmm in diameter, and between five and twenty mm in length. The bottomvial joint 224 has a top threaded joint 226 for screwing to the glassadapter 212, having threads 228, and a bottom threaded joint 227 forscrewing to the disposable glass vial 214, as shown in FIG. 2. Thethread of the joint 226 preferably uses G.P.I. (Glass PackagingInstitute) 20-400 thread. The inside diameter of the threaded joint 226is approximately twenty mm. The numeral “400” designates a specificstyle of the finish. FIG. 15 illustrates an alternative embodiment ofadapter 212. As shown, a stopcock or valve 221 may be integrated intothe vacuum take-off port 220 in order to adjust the vacuum and preventthe filtrate from being sucked into the vacuum line. Adapter 212 ispreferably formed from conventional glass, but may alternatively beformed from polymer materials, metal or any other suitable material.

FIG. 9 illustrates an alternative vacuum take-off adapter 412, for usewith the kit of FIG. 1, with a bottom ground joint 424 and a filterfunnel screw-threaded joint 422. The glass adapter 412 can replaceadapter 112. The adapter 412 has an interface screw-threaded joint 436on its top end, with an inner diameter between approximately five andsixteen mm. A cap 438, having an aperture formed therethrough, and asealing ring 439 are placed on the interface screw-threaded joint 436 toseal an attached filter funnel, which functions to adjust a position ofa flow discharge end of the funnel. A vacuum take-off port 420 isfurther provided.

FIG. 10 illustrates an alternative vacuum take-off adapter 512, for usewith the kit of FIG. 2, having a bottom vial joint 524 and a funnelscrew threaded joint 522. A side vacuum port 520 extends outwardly, asshown. The adapter 512 includes a funnel screw-threaded joint 536 on itstop end. To connect the adapter 512 to a funnel, a cap 538, having anaperture formed therethrough, is provided for receiving a flow dischargeend of the funnel, and positioning the flow discharge end beneath theside vacuum port 520. A sealing ring 539 and the cap 538 are placed onthe funnel screw-threaded joint 536 to seal an attached funnel. Thebottom vial joint 524 has an interface screw-threaded joint 526 thatattaches to the adapter 512 by threads 528, and a vial screw-threadedjoint 527 for coupling with a receiving receptacle or vial.

FIG. 11 illustrates adapter 312 of the kit of FIG. 3. Adapter 312includes a stopper 324 having an aperture formed centrally therethrough.The adapter 312 is designed for coupling with a vacuum Erlenmeyer shapedfiltering flask, such as exemplary flask 314 of FIG. 3. The stopper 324is formed from a polymer material, such as rubber, silicone rubber orneoprene. Glass tubing 330, with funnel ground joint 322 formed on itstop end, is inserted tightly into the center of the stopper 324. Theglass funnel ground joint 322 has a diameter between approximately fiveand sixteen mm, and a length between approximately five and twenty mm.

FIG. 12 illustrates an alternative adapter 612, for use with the kit ofFIG. 3, with a screw-threaded joint 622 on its top end. The stopper 624is formed from polymer materials, such as rubber, silicone rubber orneoprene and is similar to stopper 324 except for the screw-threadedjoint 622. The adapter 612 is used to couple a filter funnel with thevacuum Erlenmeyer shaped filtering flask. A glass screw threaded tube630 is inserted tightly into the center of the stopper 624. A cap 638,having an aperture formed therethrough and a sealing ring 639, areplaced on a screw-threaded top 636 of the adapter 612 to seal anattached filter funnel. Thus, the flow discharge end of the funnel ispositioned below the vacuum take-off port when the kit is assembled.

FIG. 13 illustrates the disposable glass-receiving receptacle 214 ofFIG. 2. Receptacle 214 includes a screw-threaded joint 230. The diameterof the threaded joint 230 is preferably between twenty and thirty mm. Atypical diameter of the joint 230 is approximately twenty-three mm,fitting G.P.I. 20-400 thread. The vial 214 has a semi-round bottom toprevent cracking under negative or positive pressure. The volume of thevial 214 is preferably between 60 and 300 mL. Multiple vials havingdiffering volumes may be provided, such as an 100 mL vial and a 200 mL,for example.

FIG. 16 illustrates an alternative cone-shaped disposable filter funnel610, to be used with any of the kits of FIG. 1, 2 or 3. Funnel 610includes an upper portion 602, having a substantially frusto-conicalcontour, with a long stem 615 projecting downwardly therefrom. The upperportion 602 has an open upper end 625, and an annular flange 604 isformed within the upper portion 602, adjacent the junction between thelower end of upper portion 602 and the stem 615, as shown. Filter disc619 is removably received by annular flange 604, as shown. As describedabove, filter disc 619 may be formed from a disposable, porous polymericmaterial, or may be formed from fritted glass or the like. As a furtheralternative, the filter disc 619 may be formed as a polymer disc. FIG.20 illustrates exemplary polymer disc 619, having a main body 700 with aplurality of relatively small apertures or pores 706 formedtherethrough. Polymer disc 619 is covered in disposable filter paper ora porous, polymeric membrane in order to trap the solute or insolublematerials. FIG. 21 illustrates an alternative polymer disc 819 having amain body 800 and a plurality of slots 802 formed in an upper surfacethereof. A central aperture or pore 804 is further formed therethrough.

FIG. 17 illustrates an alternative cone-shaped disposable filter funnel710, similar to funnel 610 described above. Funnel 710 includes an upperportion 702, having a substantially frusto-conical contour, with a longstem 715 projecting downwardly therefrom. The upper portion 702 has anopen upper end 725. Instead of the annular flange 604 of funnel 610, thefilter disc 719 is formed integrally with the upper portion 702, asshown.

FIG. 18 illustrates a further alternative filter funnel 810, to be usedwith any of the kits of FIG. 1, 2 or 3. Funnel 810 includes asubstantially cylindrical upper portion 802 with a long stem 815projecting downwardly therefrom. The upper portion 802 has an open upperend 825, and an annular flange 804 is formed within the upper portion802, adjacent the junction between the lower end of upper portion 802and the stem 815, as shown. Filter disc 619 is removably received byannular flange 804, as shown. As described above, filter disc 619 may beformed from a disposable, porous polymeric material, or may be formedfrom fritted glass or the like. Filter disc 619 may, alternatively, bereplaced by filter discs 719 or 819, as desired. As a furtheralternative, the filter disc 619 is wrapped in disposable filter paper.

FIG. 19 shows an alternative filter funnel 850, similar in contour tofilter funnel 810, described above, but lacking the inner, annularflange 804. Funnel 850 includes a lower, stem portion 860 and an upperportion 862, having an open, upper end 855. A filter disc, such asfilter disc 719, described above, for example, is received within theupper portion 862 and the filter funnel 850 and/or the filter disc 719are sized such that the filter disc 719 mates with the innercircumferential wall of the funnel 850 at or near the junction betweenthe upper portion 862 and the lower portion 860. The filter disc 719 isheld in place by frictional engagement with the inner wall. Filter disc719 may, alternatively, be replaced by filter discs 819, as desired. Asa further alternative, the filter disc 719 is wrapped in disposablefilter paper.

With reference to FIG. 22, another embodiment of the disposablepolymer-structured filtering kit, generally indicated by numeral 1000,is shown. The kit 1000 includes a disposable polymer-structuredfiltering funnel 1010, a glass vacuum take-off adapter 1012, andreusable glass flask or disposable vial 1014. Funnel 1010, adapter 1012and flask or vial 1014 may have any of the above-describedconfigurations, as FIG. 22 is intended to illustrate an alternativewhere flask or vial 1014 is positioned within adapter 1012, rather thanbeneath it.

As in the previous embodiments, the funnel 1010 has a stem 1015 with aflow discharge end 1016 formed at the distal tip thereof. The stem 1015,however, extends within the glass vacuum take-off adapter 1012 and intothe reusable flask or disposable vial 1014. The flow discharge end 1016extends into the flask 1014 to prevent contamination of adapter 1012 byfiltrate when under negative pressure from an attached vacuum source(not shown). A polymer fritted filter 1019 is placed on the bottom ofthe barrel 1018 of funnel 1010 for trapping insoluble materials. Thefunnel 1010 further includes an inner joint 101 7 positioned between thestem 1015 and barrel 1018. The inner joint 1017 provides a snug andsecure fit between the funnel 1010 and the adapter 1012.

The glass vacuum take-off adapter 1012 has a vacuum take-off port 1020for connection to the vacuum source, and a funnel ground joint 1022. Acap 1025, formed from a polymer material, is further provided forsealing the adapter. The funnel ground joint 1022 receives the stem 1015of the funnel 1010 and the inner joint 1017 of the funnel 1010 fits thefunnel ground joint 1022. Rather than the bottom flask ground joint ofthe previous embodiments, a tube 1024 is provided within the adapter1012, as shown, at the upper end thereof, so that stem 1015 passesthrough the tube 1024 and is positioned so that the flow discharge end1016 is received within the flask or vial 1014. Glass tube 1024, withfunnel ground joint 1022 on its top end, are inserted tightly throughthe center of cap 1025. The flask or vial 1014 is a commonly usedreceptacle in chemistry laboratories, and it should be understood thatthe shape and relative dimensions of flask 1014 are shown for exemplarypurposes only. The glass funnel ground joint 1022 preferably has adiameter between approximately five and sixteen mm, and a length betweenapproximately five and twenty mm.

After filtration is complete, the funnel 1010 is removed, safelydiscarded and disposed of, and replaced with another disposablepolymer-structured filtering funnel. The cap 1025 of adapter 1012 isalso opened to remove the flask or vial 1014. The adapter 1012 does notneed to be replaced, as the length of the stem 1015 of the funnel 1010positions the distal end of the flow discharge end 1016 within the flaskor vial 1014, thus removing the risk of contamination during filtration.

It is to be understood that the present invention is not limited to theembodiments described above, but encompasses any and all embodimentswithin the scope of the following claims.

1-20. (canceled)
 21. A disposable polymer-structured filtering kit,comprising: a disposable funnel having an upper portion and a detachablelower portion, the lower portion comprising a base, a top end of saidbase having a concavity and the lower end thereof defining a stem havinga flow discharge end positioned at a distal tip thereof; a filter discreceived within the concavity of the lower portion of the funnel, thefiltering funnel being constructed of a polymer; a vacuum take-offadapter having a port adapted for connection to an external vacuumsource, the vacuum-take off adapter having a body portion with a funnelengaging end and a flask or vial engaging end, wherein the funnelengaging end of the vacuum take-off adapter receives the lower portionof the filtering funnel, and wherein the vacuum take-off adapter has afunnel joint that receives the stem of the funnel; and a bottle flask orvial releasably connected to the adapter at the flask or vial engagingend; wherein the stem passes through a joint that is positioned withinan upper portion of the vacuum take-off adapter such that the flowdischarge end is positioned within the bottle flask or vial, such thatthe distal tip of the stem extends past the adapter when the funnel,adapter and flask are assembled.
 22. The polymer-structured filteringkit of claim 21, wherein the filter disc is formed from a porouspolymeric material.
 23. The polymer-structured filtering kit of claim22, wherein the polymeric material of the filtering funnel and theporous polymeric material of the filter disc are selected from the groupconsisting of polypropylene, acrylic, polycarbonate, styrene,polyfluoroethylene, polyvinylidene fluoride, and polyethylene.
 24. Thepolymer-structured filtering kit of claim 21, wherein the filter disccomprises a main body having at least one aperture formed therethrough.25. The polymer-structured filtering kit of claim 24, further comprisingat least one sheet of filter paper, the filter disc being releasablywrapped in the at least one sheet of filter paper.
 26. The disposablepolymer-structured filtering kit of claim 21, wherein the stem has aminimum length of twenty millimeters and a preferred length of eightymillimeters.
 27. The disposable polymer-structured filtering kit ofclaim 21, wherein the stem has an inner joint which fits the funnelground joint of the glass adapter tightly to prevent leakage.
 28. Thedisposable polymer-structured filtering kit of claim 21, wherein theflask has a joint in size of 14 mm/20 mm, 19 mm/22 mm, 24 mm/25 mm, 24mm/40 mm or 29 mm/42 mm.